1. Definition and Alloys
Aluminum foil is a thin aluminum product manufactured by rolling aluminum strip to a thickness typically ranging from 0.0045 to 0.2 mm. Products above approximately 0.2 mm are generally classified as aluminum strip rather than foil. Double-zero foil, commonly referring to foil with a thickness of ≤0.006 mm, represents the lightweight end of aluminum foil production and is widely used where material efficiency and low weight are important.
Common foil alloys include 8011, 1235, 1100, 1060, and 3003, with the appropriate alloy selected according to strength, formability, conductivity, and end-use requirements.
8011 is an Al-Fe-Si alloy widely used for pharmaceutical packaging, food packaging, household foil, lids, and other general-purpose foil applications. It provides a good balance of strength, formability, and corrosion resistance.
1235 and 1100 are high-purity aluminum grades commonly selected for applications requiring excellent electrical conductivity and formability, including capacitor foil and certain battery-related applications. 1060 is another high-purity aluminum alloy used for general-purpose foil and electrical or thermal applications.
3003 contains manganese and provides higher strength than the commercially pure aluminum grades. It is therefore commonly considered for containers, trays, heat-transfer applications, and other products where additional mechanical strength is required.
Typical tempers include O temper (soft) and various H tempers (work-hardened). O temper foil offers excellent flexibility and formability and is widely used for packaging, while harder H temper products are selected when greater strength, stiffness, or handling performance is required.
2. Key Properties
| Property | Typical Value |
|---|---|
| Thermal conductivity | ~230 W/m·K |
| Electrical conductivity | ~60% IACS (pure grades) |
| Oxygen/water-vapour permeability | Near-zero above ~25 µm* |
| Reflectivity | ~85–95% |
| Density | 2.71 g/cm³ |
Aluminum foil combines low density, high thermal conductivity, electrical conductivity, reflectivity, and excellent barrier performance in a very thin material. These properties are major reasons why aluminum foil is used in packaging, thermal management, electrical products, and insulation systems.
Its density of approximately 2.71 g/cm³ allows manufacturers to reduce material weight while maintaining useful mechanical and barrier performance. Aluminum foil also reflects a high proportion of radiant heat and light, making it useful in thermal insulation and heat-reflective applications.
The barrier performance depends on foil thickness, alloy, pinhole control, surface condition, and processing. Foil above approximately 25 µm can provide an extremely effective barrier against oxygen and water vapor when manufactured properly.
3. Functions
Barrier: Aluminum foil provides an effective barrier against oxygen, moisture, light, aroma, and other external influences. This helps protect food, pharmaceutical products, and other sensitive contents while supporting longer shelf life.
Shielding: Aluminum foil can block or reduce electromagnetic radiation and radio-frequency interference, making it useful for electronics, communication equipment, cables, and EMI shielding applications.
Heat management: Aluminum has high thermal conductivity and excellent reflectivity. It can transfer heat efficiently while reflecting radiant heat, making foil useful for HVAC applications, insulation facings, heat exchangers, heat-transfer components, and bakeware.
Formability: Aluminum foil can be easily folded, embossed, laminated, slit, stamped, and die-cut. This allows manufacturers to convert it into complex packaging structures and customized components.
Recyclability: Aluminum can be recycled repeatedly without losing its fundamental material properties. Recycling aluminum requires only a small fraction of the energy needed for primary aluminum production, with commonly cited figures of around 5% of the energy required for primary production, depending on the recycling system and process.
4. Applications
Lightweight aluminum foil is used across a wide range of industries because one thin material can provide barrier protection, conductivity, heat management, shielding, and excellent formability.
Typical applications include food and pharmaceutical packaging, such as blister packs, sachets, lidding foil, and laminated packaging. Aluminum foil is also widely used as household foil for cooking, wrapping, and food storage.
In industrial applications, aluminum foil is used for cable sheathing, HVAC duct facings, insulation reflective layers, and thermal management components. Its electrical conductivity also makes suitable aluminum grades useful in capacitor foil and lithium-battery current collectors, where alloy purity, thickness control, surface quality, and electrical performance are important.
Additional applications include EMI shielding for electronic equipment and communication systems, as well as laminated structures where aluminum foil acts as a protective barrier layer.
For commercial supply, buyers should specify the required alloy, temper, thickness, width, surface condition, pinhole requirements, mechanical properties, and end application. These parameters help the supplier select the most appropriate lightweight aluminum foil material for the intended production process and performance requirements.
